Disconnector switch



2 Sheets-Sheet l M. LEE ET AL DISCONNECTOR SWITCH Filed Feb. 4, 1945 May 2,1944.

L g g INVENTORS fi'w'zgf'reaer Marti/z hm QW mw mm ww May 2, 1944. M, EE ET AL DISCONNECTOR SWITCH Filed Feb. 4, 1945 2 Sheets-Sheet 2 Mal-win, Le INVENTORS 45' Iraq/2y fieaIeric'fi'Mafi/ysm ATTORNEY Patented May 2, 1944 DISCONNECTOR SWITCH Marvin Lee, Rye, and Irving Frederick Matthysse,

New York, N. Y., assignors to Bumdy Engineering Company, Inc., a corporation of New York Application February 4, 1943, Serial No. 474,750

6 Claims.

This invention relates to a disconnecting switch whose contact blades may be permanently attached to the outgoing cable, removed at will from a switch base pivot, and transported with the cable.

In the building of ships a great deal of welding is now being done, to a large extent replacing riveting. The motor generator set supplying the current to the welding electrode is mounted on the ship and when the ship is moved from one working position to another, approaching the water's edge, the cable has to be disconnected at the safety switch and reconnected at the new position. It is inconvenient to have an electrician available at all times for this process of connecting and disconnecting the cable, and therefore it is an object of this invention to provide a device that permits the connection to be made by an unskilled workman quickly and safely, and without danger of reversing phases. Another object is to provide the disconnector switch and attaching cable as a unitary assembly.

Plug and receptacle connectors which have been used for similar purposes have the disadvantage of poor contacts between the male and female conducting members. Experience has shown that the type of contacts employed in the plugs and receptacles frequently overheat under full load, particularly in the larger sizes. This condition is aggravated by wear after frequent use.

High pressure between contacts is necessary for a good electrical connection. However, the pressure between contacts of the ordinary plug and receptacle is limited due to the fact that the force required to insert the plug into the receptacle is the result of friction caused by the contact pressure. Therefore it is a further object of this invention to provide a disconnector switch with switch blades of the leverage type having means for removing the blades from their fulcrums. Due to the leverage obtained in this manner, much greater contact pressure may be employed than is possible in the plug and receptacle connectors.

Another object is to provide a disconnector switch with a switch blade round connection which automatically grounds" the ground conductor of the outgoing cable when the disconnector switch is closed. This makes it impossible to connect the phase conductors without connecting the ground conductor.

We further may employ a safety switch to open the circuit before the disconnector switch is opened, to avoid arcing at the contacts. It is a further object of this invention to provide, in combination, a safety switch and a disconnector switch with means for preventing the disconnector switch from being opened unless the safety switch is open. This is accomplished by placing both within the same housing in such a manner that when the door of the housing is closed the disconnector switch is locked in the closed position. The door is interlocked with the safety switch operating handle so that the door cannot be opened unless the safety switch is open, and therefore the disconnector switch cannot be opened unless the safety switch is open.

Another object is to provide a disconnector switch whose blades can engage only the proper switch clips. This prevents a careless workman from reversing the phases by incorrectly inserting the blades in the switch clips.

We accomplish these and other objects and obtain our new results as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawings, in which:

Fig. 1 is a plan view of our disconnector switch and safety switch installed in a switch box (with cover partially removed) Fig. 2 is a side elevation of the same with the side of the switch box partially removed.

Fig. 3 is a perspective view of the end of the disconnector switch blade.

Fig. 4 is a side elevation of a portion of the disconnector switch with a modified ground connection.

Fig. 5 is a sectional view of the disconnector switch through the plane 5-5 of Fig. 4.

Referring to the drawings, Figs. 1 and 2, reference numeral l0 designates a switch box, provided with hinges ll supporting the lid l2. The switch box contains a quick make and break safety switch l3 to which is connected the power source (not shown), and the disconnector switch M which leads to the operating apparatus as will hereinafter be explained.

Extending through the side of the switch box is safety switch handle IS. The handle I5, box l0, safety switch I3, are of a type well-known in the art as a standard quick make and break interlocking cover switch. In this type of switch. the

handle must be pulled to open position in order to open the switch box. Moreover, in this position, the switch cannot be closed when the lid of the box is open.

In Fig. 2, the contact blades l6 are shown engaging the corresponding safety switch spring contact clips l1, mounted on the insulating base ll, supported on bracket 3, secured on the switch box floor 20. A jumper braid 2| connects the contact clips I I to the conducting mounting strips 22 of the disconnector switch l4, constituting the switch terminals.

An insulating base block 23 supports the strips 22 to the metal box 20.

The disconnector switch |4 illustrated is of the four pole type for a three phase four wire cable 24 as shown. The fourth lead is the neutral lead 25, and is shown carried through both switches without grounding. The remaining leads 25, 21 and 25, together with the neutral lead 25 are enclosed within the insulated cable 24, and may be presumed to be connected to a welding apparatus or other device, not shown.

A portion of the switch, containing a handle, blades and associated connections which may be separated from the disconnector switch l4, and removed as a unitary assembly with the end of the cable, is designated as the lack 35. It comprises in detail a metal handle 3|, divided in two halves and secured together about the insulation of the cable 24 by screws 32. Integrally extending from the handle 30 are four supporting legs 33, rectangularly positioned, provided with apertured lugs 34 for attachment to a pair of insulating blocks 35 by means of bolts 35, The insulating blocks 35 are locked together by four bolts 31. Insulated leads 25, 25, 21 and 28 are secured to the connections, 1. e. pin type connectors 35 passing through grooves 39, in the blocks 35, and terminate in apertured and slotted clamping plates 40 into which slots are secured the switch knife blades 4|, by cap screws 42. The insulating block bolts 31 pass through openings in the pin connectors 35 and prevent rotation of the knife blades 4| by keeping the faces of the blades parallel. The switch knife blades 4| are provided with U-shaped slots 43 at their free ends, as shown in Fig. 3, which engage the pins 44 supported on the hinge block 45. The hinge blocks are U-shaped metal sections with flat bases and the pins extend across the two legs of the block at their free ends to form a fulcrum for the U-shaped slots 43 of the knife blades 4|. The hinge blocks 45 are supported on the mounting strips 22 to which the Jumper braid 2| is connected, leading from the safety switch l3, and are bolted as at 45 to the insulating block 23.

Bolts 4'! secure the spring switch clips 48 to the mounting strips 22 at a suitable point on the knife blades 4|. The switch clips are U- shaped to facilitate receiving the knife blades, and are compressed thereon to insure contact by the wire springs 49 supported thereon. Screws 50 lock the insulating block 23 to the floor 25 of the switch box I II.

A slotted opening in the end 52 of the switch box In, permits the handle 3| of the Jack 30 to be projected therethrough, and a cut-out extension 53 riveted as at 54 to the lid I 2 of the box abuts the surface of the handle 3| in a semicircular engagement securing the Jack in position when inserted into the disconnector switch.

The conductors are connected to their respective connectors 35 clamped to the knife blades 4| and the current from the Jumper braids 2| enter the mounting strips 22 where it passes to the spring clips 45, where contact with the switch knife blades 4| is made.

In the event a workman desires to remove the jack 30, the handle ii for the safety switch |3 must be thrown to open position. This allows the lid i2 of the switch box II to be opened. and with the power disconnected, the end of the cable 24 with handle 3| attached to the insulating blocks 35 together with blades 4|, constituting the Jack 30, are removed as a unit from the spring clips 45 and the pins 44 of the hinge blocks 45 by pivoting the ends of the blades 4| about the pins 44, as shown in dotted lines in Fig. 2, and freeing the pins through the slots 43 of the blades.

While neutrallead 25 of the three phase system is shown provided with its own switch blade hin e block, jumper blade, etc., the switch may employ only three knife blades, and the ground lead may be connected as shown in Figs. 4 and 5. Here the ground cable 50 is secured to the U- bolt 5|, which passes through apertures in the supporting frame 52 of the Jack 53, and locked thereto by nuts 54, At the opposite side the frame 52 terminates in a knife blade 65 inserted within a spring clip 65 compressed by spring 51. A bolt 55 secures the clip 55 to clip platform 59, which in turn is mounted to the metal base 20 of the switch box It by means of the screws 10. Thus, in the downward stroke of the jack 53, to establish connection with the main current source, the ground connection may be established by this auxiliary means.

In Fig. l, the distance between switch blades 4| from center to center, may be unequal. Thus, incorrect insertion of the jack will be made impossible, for a rotation about its longitudinal axis of the jack will not establish a correct matching of the fulcrums and switch clips. The jack under the unequal spacing of the engaging members can only be inserted when in correct position.

In the foregoing devices, we have provided a disconnector type of switch which may be easily withdrawn and inserted in a highly efllcient manner, by a relatively unskilled person. Our disconnector switch employs the spring type clips found in knife switches having blades with sufficlent leverage from the fulcrum points to operate the high pressure spring clips. Associated with the disconnector switch is a safety switch with interlocking switch box cover to prevent accidental withdrawal of the disconnector Jack under live loads. The disconnector switch may additionally be provided with grounding means and unequally spaced blades to insure proper alignment.

Our disconnector switch may be installed in its own switch box or used in conjunction with other safety cut-out devices. The jack is combined with the cable itself to form a unitary assembly to facilitate removal and use.

We have thus described our invention, but we desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of our invention, and, therefore, we claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of our invention are attained, and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these ob- ,iects and accomplish these results.

What we claim and desire to secure by Letters Patent is as follows:

1. A disconnector switch for connection to a device requiring electric current, said switch having a terminal and a connection to a cable leading to the device, comprising in combination a handle; a knife blade forming a rigid unitary structure therewith; means for connecting the cable to the knife blade; a hinge block for pivotally supporting the knife blade; a spring contact clip for engaging the knife blade; means for connecting the contact clip to the terminal; and means for readily detaching the knife blades from the hinge block and removing the handle, knife blade and cable connection as a unitary assembly from the disconnector switch.

2. A disconnector switch for connection to a device requiring electric current, said switch having a terminal and a connection to a cable lead ing to the device, comprising in combination an insulated handle; a knife blade forming a rigid unitary structure therewith; means for connecting the cable to the knife blade through said handle; a hinge block for pivotally supporting the knife blade; 2. spring contact clip for engaging the knife blade; means for connecting the contact clip to the terminal; and means for readily detaching the knife blades from the hinge. block and removing the handle, knife blade and cable connection as a unitary assembly from the disconnector switch.

3. A disconnector switch for connection to a device requiring electric current, said switch having terminals and connections to a multi-conductor cable leading to the device, comprising an insulated handle; a plurality of knife blades forming a rigid unitary structure therewith; means for connecting each of the conductors to a knife blade; a hinge block for each of the knife blades for pivotally supporting the same; a spring contact clip for engaging each of the knife blades; means for connecting each of the contact clips to one of the terminals; said knife blades and corresponding contact clips being unequally spaced from each other so that engagement of the blades and contact clips can occur only when the knife blades are inserted into their proper contact clips.

4. A disconnector switch for connection to a device requiring electric current, said switch having a terminal and connections to a cable provided with a ground lead leading to the device,

comprising a handle; a knife blade forming a rigid unitary structure therewith; insulation positioned between said handle and knife blade; a hinge block for pivotally supporting the knife blade; a spring contact clip for engagement with the knife blade; means for connecting the contact clip to the terminal; a ground blade projecting from said handle in a direction normal to the knife blade; means for connecting the ground lead to said handle; a ground contact clip for engagement with said ground blade; terminal means for the ground contact clip; and means whereby the closing of the disconnector switch will simultaneously connect the ground blade to the ground contact clip.

5. A switch, comprising in combination a quick make and break safety switch leading to a source of supply; a disconnector switch in series therewith for connection to a device requiring electric current; and a housing therefor having a lid; means for automatically locking the lid of the housing when the safety switch is in closed position; said disconnector switch comprising a knife blade, handle forming a rigid unitary structure therewith, and means for connecting the knife blade to a cable, forming a rigid unitary assembly; a hinge block for pivotally and detachably supporting the knife blade thereto; said housing having an open slot for permitting said handle to be projected therethrough when the disconnector switch is in closed position, said lid when in closed position blocking the open end of the slot, to prevent removal of the handle.

6. A disconnector switch for connection to a device requiring electric current, said switch having a terminal, and a connection to a cable leading to the device, comprising a U-shaped hinge block'provided with a pin extending from one leg of the U to the other; a spring contact clip; a conducting strip leading from the contact clip to the terminal of the disconnector switch, a readily removable jack consisting of a knife blade having a U-shaped end thereof for pivot engagement with the pin of the hinge block, a handle forming a rigid unitary structure therewith, and

* means for connecting the blade with the cable MARVIN LEE. IRVING FREDERICK MATTHYBSE. 

